The massive hack last year of the Office of Personnel Management’s system containing security clearance information affected 21.5 million people, including current and former employees, contractors and their families and friends, officials said Thursday.

That is in addition to a separate hack – also last year — of OPM’s personnel database that affected 4.2 million people. That number was previously announced.

Together, the breaches arguably comprise the most consequential cyber intrusion in U.S. government history. Administration officials have privately said they were traced to the Chinese government and appear to be for purposes of traditional espionage.

The 21.5 million figure includes 19.7 million individuals who applied for a background investigation, and 1.8 million non-applicants, predominantly spouses or people who live with the applicants. Some records also include findings from interviews conducted by background investigators, and about 1.1 million include fingerprints, officials said.